I think for a paladin of the absolute, the oath of conquest would fit very snuggly. Their tenets: Douse the Flame of Hope. Rule with an Iron Fist. Strength Above All. Those sound like very fitting tenets for the Absolute. They're from Xanathar's Guide to Everything, but I figure if they're gonna do something so tied to the plot as making us a paladin of the main antagonist, then I'd say that would be worth the effort of bringing in an outside of PHB subclass.
